Analysis of cyanide in blood by headspace solid-phase microextraction (SPME) and capillary gas chromatography

摘要

Cyanide can be extracted from whole blood samples by headspace solid-phase microextraction (SPME) with a Carbowax/divinylbenzene-coated fiber. During heating a vial of a whole blood sample containing cyanide and acetonitrile as internal standard (IS) at 50 degrees C in the presence of Na2SO4, a Carbowax/divinylbenzene-coated SPME fiber was exposed in the headspace of the vial for 45 min to allow adsorption of cyanide and IS. The fiber needle was then injected into a capillary gas chromatography (GC) instrument equipped with nitrogen-phosphorus detection. The headspace SPME-GC with a Supel-Q PLOT fused silica capillary column gave large peaks for cyanide and IS; almost no interfering peaks appeared. Recoveries of cyanide and IS from human whole blood were 3.02-4.06 % and 0.21 %, respectively. The calibration curve for cyanide added to human blood showed excellent linearity in the range of 0.04-4.0 mu g mL(-1); the detection limit was about 0.02 mu g mL(-1). The coefficients of intra-day and inter-day variation were not greater than 7.1 and 9.2 %. Good correlation (r(2) = 0.999) was found between the present SPME-GC method and the conventional microdiffusion colorimetric method. Data on determination of cyanide in rat blood after intraperitoneal administration are also presented. [References: 25]